Unlocking Accurate Synonym Comparison in SQL Compare: A Simple Fix

Have you ever been puzzled when running a database comparison and expected synonym differences are nowhere to be found? You’re not alone. Many users of database comparison tools, like Redgate’s SQL Compare, encounter a situation where changes in synonyms, particularly those pointing to different database objects across environments, seem to be overlooked. This can be particularly confusing when you know for a fact that your synonyms are configured differently between, say, your development and production databases.

This article dives into why SQL Compare might be missing these crucial synonym differences and, more importantly, provides a straightforward solution to ensure accurate and comprehensive database comparisons, especially when synonyms are involved. This is essential for maintaining database integrity across different stages of your development pipeline.

The Scenario: Synonyms Pointing to Different Objects

Consider a common database development scenario. You might have synonyms set up in your development environment that point to objects within the same environment, but these need to target different objects or even databases in your production setup.

For example, in a development environment, you might have databases named Sales_Feature and Finance_Feature. Within Sales_Feature, a synonym might be created to reference a table in Finance_Feature. This setup works well during development.

USE [SimpleTalk_1_Dev]
GO
CREATE SYNONYM dbo.MyTable FOR Compare1.dbo.MyTable
GO

However, when deploying to production, your database names might be different, perhaps simply Sales and Finance. You need your synonym in the production Sales database to correctly point to the Finance database.

USE [SimpleTalk_5_Prod]
GO
CREATE SYNONYM dbo.MyTable FOR Compare2.dbo.MyTable
GO

When you use SQL Compare to compare these development and production databases, you might be surprised to find no difference reported for these synonyms, even though they clearly point to different locations.

This is because, by default, SQL Compare operates under the assumption that database and server name variations in synonyms are intentional and expected when moving between environments. It prioritizes highlighting other types of structural differences, assuming that synonym target variations are environment-specific configurations you are already aware of.

The Solution: Adjusting Project Options for Synonym Accuracy

The solution to this issue is surprisingly simple and lies within SQL Compare’s project options. To ensure that SQL Compare accurately detects and highlights differences in synonym targets, you need to adjust a specific setting.

Within your SQL Compare project, navigate to “Edit project” and then select the “Options” tab. Scroll down within the options list, and you will find the setting labeled “Ignore database and server name in synonyms.”

This option is checked by default, which explains why SQL Compare was overlooking the synonym differences in our scenario. By unchecking this box, you instruct SQL Compare to consider the database and server names as significant components when comparing synonyms.

After unchecking “Ignore database and server name in synonyms” and re-running the comparison, you will now see the synonym differences clearly identified by SQL Compare.

This adjustment is crucial not only when database names differ but also when you are comparing databases across different SQL Server instances but with the same database names – a very common scenario in many development and deployment pipelines.

Ensuring Synonym Deployment Across Redgate Tools and DevOps Pipelines

This “Ignore database and server name in synonyms” option is not exclusive to SQL Compare. It is a core setting within the SQL Compare engine that powers a range of Redgate products designed for database development and deployment. This includes SQL Change Automation, SQL Source Control, Flyway Desktop, and various automation components within Redgate Deploy.

Therefore, if you are using any of these tools and find that synonym changes are not being deployed as expected, verifying and adjusting this option should be one of your first troubleshooting steps. Ensuring this setting is correctly configured is paramount for maintaining consistency and accuracy in your database deployments, especially within a DevOps environment where automated and reliable deployments are critical.

If you are seeking tools to streamline your database development and deployment processes in a DevOps-oriented manner, consider exploring trials of Redgate’s solutions. They offer a comprehensive suite of tools designed to enhance efficiency and reliability across your database lifecycle.